Amy Inman-Felton, researcher for the American Dietetic Association, wrote in her Apr. 1999 article "Overview of Lactose Maldigestion (Lactase Nonpersistence)":

“Recent evidence strongly suggests that people with medically confirmed lactase maldigestion [lactose intolerance] can include the recommended number of servings of milk and other dairy foods in their diet without experiencing gastrointestinal discomfort. People with lactose maldigestion [lactose intolerance] who include milk and other lactose-containing dairy foods in their diet may actually improve their tolerance to lactose.”

Apr. 1999